Birth weight
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Baby_being_weighed.jpg/220px-Baby_being_weighed.jpg)
Birth weight is the body weight of a baby at its birth.[1]
There have been numerous studies that have attempted, with varying degrees of success, to show links between birth weight and later-life conditions, including diabetes, obesity, tobacco smoking and intelligence.
Determinants
There are basically two distinct determinants for birth weight:
- The duration of gestation prior to birth, that is, the gestational age at which the child is born
![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/Weight_vs_gestational_Age.jpg/220px-Weight_vs_gestational_Age.jpg)
- The prenatal growth rate, generally measured in relation to what weight is expected for any gestational age.
The incidence of birth weight being outside what is normal is influenced by the parents in numerous ways, including:
- Genetics
- The health of the mother, particularly during the pregnancy
- Environmental factors, including exposure of the mother to secondhand smoke[2]
- Economic status of the parents gives inconsistent study findings according to a review on 2010, and remains speculative as a determinant.[3]
- Other factors, like multiple births, where each baby is likely to be outside the AGA, one more so than the other
Abnormalities
- A low birth weight can be caused either by a preterm birth (low gestational age at birth) or of the infant being small for gestational age (slow prenatal growth rate), or a combination of both.
- A very large birth weight is usually caused by the infant having been large for gestational age
Influence on adult life
Studies have been conducted to investigate how a person's birth weight can influence aspects of their future life. This includes theorised links with obesity, diabetes and intelligence.
Obesity
A baby born small or large for gestational age (either of the two extremes) is thought to have an increased risk of obesity in later life,[4][5] but it was also shown that this relationship is fully explained by maternal weight.[6]
GH therapy at a certain dose induced catch-up of lean body mass (LBM). However percentage body fat decreased in the GH-treated subjects. Bone mineral density SDS measured by DEXA increased significantly in the GH-treated group compared to the untreated subjects, though there is much debate over whether or not SGA (small for gestational age) is significantly adverse to children to warrant inducing catch-up.[7]
Diabetes
Babies that have a low birth weight are thought to have an increased risk of developing type 2 diabetes in later life.[8][9][10]
Intelligence
Some studies have shown a direct link between an increased birth weight and an increased intelligence quotient.[11][12][13]
Epidemiology
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/73/Low_birth_weight_world_map_-_DALY_-_WHO2002.svg/220px-Low_birth_weight_world_map_-_DALY_-_WHO2002.svg.png)
See also
References
- ^ Definitions from Georgia Department of Public Health. Date: 12/04/2008. Original citation: "Birthweight: Infant's weight recorded at the time of birth"
- ^ "The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General". Surgeon General of the United States. 2006-06-27. Retrieved 2009-02-07. pp. 198–205
- ^ Margerison Zilko CE (2010). "Economic contraction and birth outcomes: an integrative review". Hum Reprod Update. 16 (4): 445–458. doi:10.1093/humupd/dmp059. PMID 20085917.
{{cite journal}}
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ignored (help) - ^ "3 stages of childhood may predict obesity risk - Fitness - MSNBC.com". Retrieved 2007-11-28.
- ^ Singhal A, Wells J, Cole TJ, Fewtrell M, Lucas A (1 March 2003). "Programming of lean body mass: a link between birth weight, obesity, and cardiovascular disease?". Am J Clin Nutr. 77 (3): 726–30. PMID 12600868.
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: CS1 maint: multiple names: authors list (link) - ^ Parsons TJ, Power C, Manor O (2001). "Fetal and early life growth and body mass index from birth to early adulthood in 1958 British cohort: longitudinal study". BMJ. 323 (7325): 1331–5. doi:10.1136/bmj.323.7325.1331. PMC 60670. PMID 11739217.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ "GH Treatment Effects on Body Composition in SGA". Growth, Genetics & Hormones. 24 (1). 2008.
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ignored (help) - ^ "Low birth weight diabetes link". BBC News. 2005-02-25. Retrieved 2007-11-28.
- ^ Gillman MW, Rifas-Shiman S, Berkey CS, Field AE, Colditz GA (2003). "Maternal gestational diabetes, birth weight, and adolescent obesity". Pediatrics. 111 (3): e221–6. doi:10.1542/peds.111.3.e221. PMID 12612275.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Rich-Edwards JW; Colditz GA; Stampfer MJ; et al. (1999). "Birthweight and the risk for type 2 diabetes mellitus in adult women". Ann Intern Med. 130 (4 Pt 1): 278–84. PMID 10068385.
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ignored (help) - ^ Matte TD, Bresnahan M, Begg MD, Susser E (2001). "Influence of variation in birth weight within normal range and within sibships on IQ at age 7 years: cohort study". BMJ. 323 (7308): 310–4. doi:10.1136/bmj.323.7308.310. PMC 37317. PMID 11498487.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ "The Future of Children - Sub-Sections". Archived from the original on 2007-10-22. Retrieved 2007-11-28.
- ^ "HEALTH | Intelligence linked to birthweight". BBC News. 2001-08-09. Retrieved 2007-11-28.
- ^ "Mortality and Burden of Disease Estimates for WHO Member States in 2002" (xls). World Health Organization. 2002.
External links
- MedlinePlus Encyclopedia: Intrauterine growth restriction
- Peleg D, Kennedy CM, Hunter SK (1998). "Intrauterine growth restriction: identification and management". Am Fam Physician. 58 (2): 453–60, 466–7. PMID 9713399.
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ignored (help)CS1 maint: multiple names: authors list (link) - "Intrauterine growth restriction (IUGR)" at Health System, University of Virginia
- Fetal Growth Restriction at eMedicine
- "Researchers link low birth weight to lower achievement"
- "Management of Suspected Fetal Macrosomia"
- "Vit D linked to baby birth weight" at BBC News, 25 April 2006
- Born in Bradford - 2006 cohort study into the causes of low birth weight and infant mortality in Bradford, UK
- Intrauterine Growth Restriction Help - IUGR factors and solutions
- Walid MS, Astafyeva OV, Pomortsev AV (2007). "The IUGR prognostic scale". Arch Gynecol Obstet. 276 (6): 633–40. doi:10.1007/s00404-007-0398-1. PMID 17619893.
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ignored (help)CS1 maint: multiple names: authors list (link)